Query XML with an XPath expression

This Example shows you how to Query Xml File via XPath
expression. JAXP (Java API for XML Processing) is an interface which provides
parsing of xml documents. Here the Document BuilderFactory is used to create new
DOM parsers.XPathFactory is being used to create Xpath objects. There are some
of the methods used in code given below for Xml Query:-

DocumentBuilderFactory builderFactory =
DocumentBuilderFactory.newInstance():-This method Creates a
DocumentBuilderFactory .DocumentBuilderFactory is a Class that enables
application to obtain parser for building DOM trees from XML Document

DocumentBuilder builder = Factory.newDocumentBuilder():-This
method creates a DocumentBuilder object with the help of a
DocumentBuilderFactory.

XPathFactory factory = XPathFactory.newInstance():-This
method creates an XPathFactory. use of this class is to create XPath Objects.

XPathExpression expr = xpath.compile("//Employee[City='Haldwani']/name/text()"):-XPathExpression
is an Interface which provide access to the compiled XPathExpression i.e
("//Employee[City='Haldwani']/name/text()").

Object result = expr.evaluate(doc,
XPathConstants.NODESET):-This method evaluates the compiled XPath expression and
return the result as the specified type.